1. Field
This invention relates to a power management circuit, a power management method and a power management program, which control a power supplied to functional blocks in a hardware.
2. Background
In recent years, by progress of a miniaturization technology, there appears such integrated circuits that the functional blocks including processor cores, memories, DMAs (Direct Memory Access) are provided on one chip. In these circuits, there is a problem that increasing a circuit scale causes an increase of a consumed power.
A method to suppress the increase of the consumed power in these circuits includes a method to limit the power supplied to the functional blocks not being used.
As an example of this method, there is proposed a technique of managing the use ranges of the memories and turning off the power of memory blocks not being used (see Japanese Patent Applications Laid-open under No. 2005-196545 and No. H09-212416, for example).
By the way, when the supply of the power is controlled for each functional block, a chip area increases because the power supply system and the control circuit of the power supply are provided separately for each functional block. Therefore, there is a method for suppressing the increase of the chip area, which not controls the power for each functional block but controls the power for each unit such as “domain” into which the functional blocks are organized.
In this way, when the power control is executed for each domain, a control program that controls other functional blocks not to access to the functional blocks in the domain under the power control is embedded in the application. In this case, it is necessary for the application to execute the control such that the other functional blocks do not access to all the functional blocks belonging to the domain subjected to the control. But, this control operation is complicated in case that there are many functional blocks in the domain because this operation is different in accordance with the type of the functional block subjected to the control and the content of the power control operation. In addition, this control operation is different in accordance with the configuration of the functional blocks in the domain. Therefore, in case that the domain groupings are different even if the functional blocks have the same configuration, or changing the functional blocks or adding new functional blocks are performed in the future, it is necessary to significantly change the power control program embedded in the application, which lead to the problems including an increase of a development man-hours of the application and a deterioration of the reusability.